Brakes...Mushy sometimes, firm other times

The problem I’m having with my brakes is that they’ve been mushy at times and firm at others. It will go from firm to mushy where the brake pedal will go all the way down, to firm again and vice versa. I’ve recently bled my brakes and i’ve had this problem on and off for probably 5 or 6 months, but not to the point where my pedal would hit the floor. 93 GS auto w/ abs. only mod to brake system is steel braided brake lines. had bled at acura dealership. installed brake lines about 2 months after i had noticed the problem. thanks for any help.

master cylinder

Yeah…what’s with it being so sporadic. today my brakes were really firm. but the past few days it was off and on…

it depends how hard and fast you push on it… theres cup seals inside the master cylinder that expand when theres pressure and they are supposed to collapse when you release it… the cup seals over time get worn out… a test you can do is… when the car is off… pump the pedal a few times till it gets rock hard… then exert slow but increasing pressure to the pedal… you will notice at the top of travel itll be kinda easy to push in… then as you push harder itll get harder to push in…also check under your master cylinder along the booster… if you see blistering paint and/or fluid… it’s a good sign your master is leaking

MC.

thanx…should i replace my booster too and how hard of a job is this? i’m somewhat competent as a mechanic…thanx tho…

it’s all covered in the helm manual. :up:

not too tough.